Flow measuring devices are, as a rule, embodied as in-line measuring devices, which are insertable into a pipeline, such as, for example, into a process line of an industrial plant. Such flow measuring devices have, as a rule, at least one measuring tube, through which fluid flows during use. A Coriolis, flow measuring device can measure at least one parameter, such as, for example, mass flow rate, density, viscosity, etc., of the fluid flowing in the pipeline.
In some applications, there is the problem that the fluid to be measured tends to form accretions, is abrasive and/or attacks the material of the at least one measuring tube of a flow measuring device. This leads to the fact that the measuring tube must be relatively frequently replaced. In typical Coriolis, flow measuring devices, this is associated with significant effort and high costs. In some fields of application, such as, for example, in the foods industry, there is, furthermore, the requirement that the total system of pipelines contacted by the fluid, thus also the at least one measuring tube of an installed flow measuring device, must, after a certain duration of operation and/or in the case of a change of the fluid flowing through the system, be cleaned. This is in the case of measuring tubes of flow measuring devices, especially in the case of measuring tubes of Coriolis, flow measuring devices, complex and cost intensive. Furthermore, there is, in some fields of application, such as, for example, in medicinal fields, the requirement that the respective fluid lines, whose flow should be determined, should not have their continuity interrupted. An example of such a fluid carrying line is an infusion hose, which is, as a rule, formed of a flexible plastic tube.
Known from German publication DE 10 2008 002 215 A1 is a Coriolis, flow measuring device, in the case of which a guide unit, through which the fluid to be measured flows, is placed removably on a support unit. The guide unit and the support unit are mechanically coupled to one another. The support unit is excited in use to mechanical oscillations and the mechanical oscillations of the support unit are registered by at least one oscillation sensor. The construction described in DE 10 2008 002 215 A1 is suited especially for flow measurement of gravitationally transported solids (e.g. bulk goods).
Known from German publication DE 43 11 694 C1 is a mass flow meter working according to the Coriolis principle, which has a soft, essentially completely flexible, hose, which is secureable by force interlocking, e.g. friction interlocking, with a predetermined track on a rigid hose accommodation. The hose accommodation is, in turn, secured to an oscillatory system for movement together with the hose about a first axis. Furthermore, the hose accommodation is held rotatably relative to the oscillatory system about a second axis in such a manner that the hose accommodation can execute movement around the second axis brought about by the Coriolis forces of the mass flowing in the hose. Due to the different rotational axes, this arrangement leads to a relatively complex construction.